The Nilgiri Mountains form part of the Western Ghats in northwestern Tamil Nadu, Southern Karnataka, and eastern Kerala in India. They are located at the trijunction of three states and connect the Western Ghats with the Eastern Ghats. At least 24 of the Nilgiri Mountains’ peaks are above 2,000 metres (6,600 ft), the highest peak being Doddabetta, at 2,637 metres (8,652 ft).


The word Nilgiri, comes from Tamil words neelam (blue) + giri (mountain), has been in use since at least 1117 CE. In Tamil literature it is mentioned as Iraniyamuttam[2][3] It is thought that the bluish flowers of kurinji shrubs gave rise to the name.[4]


The Nilgiri Hills are separated from the Karnataka Plateau to the north by the Moyar River.[5]

Three national parks border portions of the Nilgiri mountains. Mudumalai National Park lies in the northern part of the range where Kerala, Karnataka, and Tamil Nadu meet, covering an area of 321 km2 (124 sq mi). Mukurthi National Park lies in the southwest part of the range, in Kerala, covering an area of 78.5 km2 (30.3 sq mi), which includes intact shola-grassland mosaic, habitat for the Nilgiri tahr. Silent Valley National Park lies just to the south and contiguous with those two parks, covering an area of 89.52 km2 (34.56 sq mi).[citation needed]